Phillies Nuggets: What’s wrong with Aaron Nola?

Aaron Nola has had a slow start to his 2019 season. (Dustin Bradford/Icon Sportswire)

Philadelphia Phillies ace Aaron Nola got his second victory of the 2019 season last Saturday in Denver against the Colorado Rockies. Nola – after one of the best seasons in Phillies history in 2018 – is actually 2-0 this season. That, however, perhaps gives you an idea of how misleading wins and losses can be for a pitcher. While Nola got a win Saturday, he labored through 5.2 innings, scattering nine hits, allowing two home runs and three earned runs total. Five starts into 2019, the 25-year-old righty has a 6.84 ERA, 6.06 FIP and -0.1 fWAR.

The biggest question mark heading into one of the most anticipated Phillies seasons ever was the starting rotation. But Nola, who finished third in National League Cy Young Award voting a season ago, was supposed to be the one sure thing. He’s been the opposite of that in the early going, which is an alarming trend, even as the Phillies hover near the top of a very talented National League East. But what’s gone wrong for Nola?

It’s always difficult to entirely rule out an injury for a pitcher. David Robertson, for example, pitched two scoreless innings in an extra-inning win over the Miami Marlins on April 14. A day later, the 34-year-old was placed on the 10-day injured list with elbow soreness. But to this point, there’s been no indication that Nola is dealing with a physical ailment. The Phillies, given the $45 million deal they inked Nola to in Spring Training, have certainly monitored Nola’s health through the early stages of the 2019 season as he’s struggled. They haven’t caught anything, and there hasn’t been a noticeable velocity drop. Nola’s average fastball velocity has been 92.9 mph, down slightly from 93.3 mph in 2018. Such a small dip isn’t a cause for concern – as the weather gets warmer, pitchers typically see slight upticks in their velocity.

It’s worth noting that Nola’s sinker – which he’s using 18.8 percent of the time in 2019, up from 14.4 percent a year ago – has actually seen a slight uptick in velocity. But the sinker hasn’t been an effective pitch for Nola in 2019, as opponents are hitting .455 against it. Opponents have a .556 batting average on balls in play against Nola’s sinker in 2019, which suggests he could be due for some positive regression. But opposing hitters hit .189 against Nola’s sinker a year ago, with a .232 batting average on balls in play – maybe that level of success with the pitch wasn’t sustainable, especially with an increased usage rate.

Perhaps even more noteworthy is that Nola hasn’t found success in the early going with his curveball, which is the pitch he utilizes at the second highest rate, behind his fastball. Five starts is a small sample size, and one of Nola’s five starts in 2019 came at Coors Field, where the altitude can sometimes eat up breaking pitches. But still, opponents are hitting .333 against Nola’s curveball in 2019, up from a meager .156 a season ago.

The most obvious problem Nola has dealt with is being victimized by the home run ball. The first pitch he threw against the Rockies last Saturday, Charlie Blackmon deposited over the right-center field wall, one of seven home runs that Nola has already surrendered in 2019. In 11 starts between September of 2018 and March/April of 2019, Nola has given up 11 home runs. In Nola’s first 27 starts of 2019, he allowed eight total home runs.

The concept of launch angle is scoffed at by some more traditional baseball fans and observers that are hesitant to embrace sabermetrics. And as the Phillies learned with Scott Kingery a year ago, using a one-size-fits-all approach for developing hitters isn’t smart. But hitters have adjusted their average launch angle against Nola, which has likely led to the drastic increase in home runs allowed. A year ago, the average launch angle hitters used against Nola was 8.0. Through his first five starts in 2019, the average launch angle hitters are using against Nola is 10.1. Launch angle may not be the most interesting topic, but it’s unavoidable in this discussion – the average launch angle against Nola in his career is 7.8. The difference in a few degrees is major.

Interestingly, Nola’s meatball percentage – yes, that’s a real statistic that is tracked – is currently at 6.6 percent, which would actually be a career-low. So too, though, is the percentage of pitches classified as meatballs that Nola throws that opponents are swinging at.

Nola also simply isn’t getting ahead in counts like he has in the past. A season ago, he threw a first pitch strike in 69 percent of at-bats. That’s down to 50 percent in 2019. Nola’s career average of first pitch swings is 26.7 percent. In his All-Star season a year ago, Nola got opposing batters to swing on 28 percent of first pitches. This season, opponents are swing at just 19.3 percent of first pitches. Again, five starts is still a relatively small sample size, but it’s not so small that having this discussion is silly.

The Phillies obviously don’t want Nola to be injured, but an injury would explain why he’s struggled so much to open the 2019 season. Perhaps Nola is dealing with a mechanical issue, though there isn’t any evidence that his release point has drastically changed from his career averages. There isn’t an easy answer to why Nola is struggling. As part of league wide adjustments, hitters are being more patient against Nola, and that’s affected how he’s attacked opponents. Great pitchers constantly find ways to out-adjust the rest of the league, a task that now faces Nola.